Summary: Eur. Phys. J. E 19, 155­162 (2006)
DOI: 10.1140/epje/e2006-00018-3 THE EUROPEAN
PHYSICAL JOURNAL E
Polyelectrolyte multilayer formation: Electrostatics
and short-range interactions
A. Shafira
and D. Andelmanb
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv,
Tel Aviv 69978, Israel
Received 6 September 2005
Published online 21 February 2006 ­ c EDP Sciences, Societ`a Italiana di Fisica, Springer-Verlag 2006
Abstract. We investigate the phenomenon of multilayer formation via layer-by-layer deposition of alternat-
ing charged polyelectrolytes. Using mean-field theory, we find that a strong short-range attraction between
the two types of polymer chains is essential for the formation of multilayers. For strong enough short-range
attraction, the adsorbed amount per layer increases (after an initial decrease), and finally it stabilizes in
the form of a polyelectrolyte multilayer that can be repeated hundreds of times. For weak short-range
attraction between any two adjacent layers, the adsorbed amount (per added layer) decays as the distance
from the surface increases, until the chains stop adsorbing altogether. The dependence of the threshold
value of the short-range attraction as function of the polymer charge fraction and salt concentration is
calculated.